The purpose of this Planning Grant is to develop operations and procedures as part of the planning process for conducting a large-scale, multi-center trial of Tinnitus Retraining Therapy (TRT). TRT is a habituation-based intervention that uses directive counseling and low-level sound therapy to facilitate habituation of the awareness of tinnitus, its annoyance, and impact on the patient's life. Millions of Americans experience tinnitus, but for about 2.5 million individuals it is severely disabling. With no other proven or more successful intervention, TRT has become the therapeutic intervention "of this decade" for disabling tinnitus. TRT, however, remains highly controversial despite many reported successes in this country and abroad. It now lacks and requires validation in a controlled clinical trial. In light of a real need for a rigorous controlled study of TRT, we will develop, organize, and plan a formal randomized, double-blind, placebo- controlled, longitudinal clinical trial of TRT. The trial will be conducted at flagship Army, Air Force, and Navy Medical Centers with active duty and retired military personnel and their dependents. The likely higher incidence of noise-induced tinnitus (than in the general population) and the great diversity of this study population make the U.S. Armed Forces an ideal study group for a clinical trial of TRT. The 3x2 trial design will incorporate six treatment arms to control for the treatment effects of directive counseling and sound therapy, including a double-blind placebo sound therapy and a "no treatment" control arm to establish the natural history of tinnitus. The trial will use a repeated- measures questionnaire, psychoacoustic, and audiologic data as outcome measures to evaluate the validity and efficacy of TRT and its component parts in habituating the perceived tinnitus sensation, awareness, annoyance, and overall impact on life (Aim 1); characterize and monitor the temporal courses of the habituation effects over the course of TRT in relation to the non- treatment control arm and those arms receiving alternative placebo and partial treatments (lacking either the counseling or sound therapy components) (Aim 2); establish the permanence and sustained benefits of TRT and the alternative interventions, post-treatment (Aim 3); and develop statistical models and methods to establish and predict the success of TRT, the treatment effects from directive counseling and sound therapy, the mechanisms by which each works, and the target population for TRT (Aim 4).